This invention pertains to pass doors in operable walls movable to partition large rooms into smaller rooms, and, in particular, to a pass door drop seal which forms a sound barrier between the closed pass door and the floor above which the pass door is suspended.
Operable walls or partitions, also known as movable wall panel systems, find useful application in a variety of venues, such as classrooms, offices, convention centers and hospitals. In these venues, the operable walls can be utilized to efficiently compartmentalize interior space into a multitude of separate, smaller rooms. As it is frequently desirable for persons to be able to pass back and forth between the smaller rooms without opening, i.e. stacking, the operable walls, pass doors are often provided in the operable walls. In particular, usually an operable partition panel is provided with a doorway in which is installed a pass door which may be swingably hinged and latched as are conventional room doors.
One shortcoming associated with pass doors pertains to their acoustical integrity. In order for the rooms which are accessed by a pass door to provide a useful working environment free from acoustic disturbances, the pass doors when closed should serve as effective sound barriers. One passageway for sound to undesirably pass by a closed pass door between adjoining rooms is the space between the pass door's bottom edge and the floor.
In an effort to block this sound passageway, a variety of vertical expansion seals or drop seals have previously been employed. One type of drop seal, which is also known as a float seal, includes a strip of resilient material stretching the length of and attached to the bottom edge of the pass door. The resilient strip hangs down to the floor and floats or drags along the floor when the pass door is opened. These float seals also drag along the floor when the operable wall system is stacked or extended. While capable of blocking some portion of sounds, drop seals of this type have generally failed to provide adequate sound barrier properties for many particular installations.
Another known type of pass door drop seal is an adjustable fixed sweep or seal. This type of seal includes a drop seal channel attached to vertically extending rods received within tubes attached to the pass door at either pass door side edge. Rod engaging screws which extend through the tubes can be tightened to lock the rods within the tubes at a selected longitudinal location. The adjustable fixed seal installer can mechanically lower and set the seal at a fixed, operational height after the pass door operable partition is installed such that the seal contacts the floor. When the pass door is opened, the seal sweeps along the floor. Adjustable fixed seals have been utilized in continuously hinged, electrically driven operable partitions which employ automatic drop seals in intermediate partition panels. However, as each of these intermediate partition drop seals is typically actuated by the drop seal of the immediately forward or preceding partition, pass doors are normally limited to being near the most trailing panel, as pass doors are not equipped with these automated seals and therefore can not actuate the automatic drop seals of further trailing panels. Each panel trailing the pass door panel then may also be equipped with adjustable fixed seals.
Another known type of pass door drop seal is a crank down drop seal which is mechanically lowered to an operational alignment by an installer. Specifically, after the operable wall system has been extended and while the pass door is open, the drop seal is manually lowered or screwed down to an elevation spaced above the floor. This space allows the door to be swung open without the drop seal engaging the floor. In order to provide a sound barrier seal between the closed pass door and floor, the crank down drop seal includes a spring mechanism, cooperating with the doorjamb, which biases the drop seal downward into contact with the floor when the door is fully closed.
One shortcoming of this crank down drop seal is that cranking the drop seal down to an appropriate operational height requires trial and error and may therefore be burdensome on an installer. Another shortcoming of this crank down drop seal is that while useful for an operable partition separately movable relative to the other partitions, it is generally inappropriate for use with continuously hinged, driven operable partitions. In particular, to properly stack a standard operable partition which includes a pass door, the pass door needs to be closed, and as a result the seal of the crank down drop seal engages the floor. Unless an operator remembers to manually retract or crank up the drop seal in the closed pass door before moving the pass door partition with the other continuously hinged partitions, the drop seal will be dragged against the floor during partition movement. This dragging movement may damage the drop seal or the floor. Thus, it is desirable to provide a drop seal for pass doors which addresses these disadvantages.